The one that gets me the most is could care less, when i went to america it confused me and i tried to explain to a few friends its couldnt care less but it just made them say could care less more, lol.

Here is a little youtube clip from David Mitchell - comedian from UK on couldnt/could. i have forgot how to link the clip, sorry about that. Its a great clip though, well unless you are American with no sense of humour!